The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Many images, such as photographs and video recordings, are stored with metadata that indicates the geographic location at which the image was created. For example, a camera equipped with a Global Positioning Service (GPS) receiver determines the position of the camera in the GPS coordinate system at the time a photograph is taken and stores the determined GPS coordinates with the photograph. These coordinates later can be used to determine what is depicted in the photograph (e.g., which building in what city), for example.
However, in some situations, metadata stored with an image fails to indicate the geographic location with the desired precision. For example, GPS generally has a margin of error of approximately 25 meters. In so-called “urban canyons,” or city locations at which tall buildings obscure or reflect GPS signals, the problem of imprecise coordinates is particularly prevalent.